Post installation problem

Question

Hey guys! Just installed Yosemite on my pc and everything went fine . The thing is I can only boot into safe mode with the boot flags npci=0x2000 -x -v. The problem is that no usb stick is recognized where I have the appropriate kexts so no sound no Ethernet at all. Any way to fix that? Thanks in advance !

I have never experienced the error "Couldn't find IOSurfaceRootUserCleint for task" before but in the verbose log, the prelinked kernel has expired, you can try rebuilding it by booting in Single user mode
boot with kernel flag -s
#Run the following commands one by one
mount -uw /
kextcache -i /
reboot
Let me know the results

First problem - After playing a video on any player, only the sound is played and the picture will not be displayed. I tried different settings with VLC but the image is still not.
The second problem - In Safari is scrolling OK, in Chrome the image is jerking for scrolling.
Default is Sierra after installing with HD 7000, does not help changing to HD 630
Is there anything else to do with the graphics card ?
I have already written in the forum but no one can help me. Help me please.